Drainboard



FIG. 1 is a top perspective view of a drainboard, showing my new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front elevational view thereof; and

FIG. 5 is a rear elevational view thereof. 

The ornamental design for a drainboard, as shown. 